Circuits for electron-discharge devices



Feb. 10, 1931. G. w. CARPENTER 7 CIRCUITS FOR ELECTRON DISCHARGE DEVICESFiled Oct. 3, 1923 AAAA - IhQentor: G l enn \A/. Cam-pent er.

His Attorney.

Patented Feb. 10, 1931 UNITED STATES;

GLENN W. CARPENTER, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELEC-PATENT OFFICE {ERIC COMPANY, A CORPORATION OF NEW YORK CIRCUITS FORELECTRON-DISCHARGE DEVICES Application filed October 3, 1923. Serial No.666,223.

My present invention relates to circuits adapted for use with electrondischarge amplifiers and detectors, and more particularly toarrangements for eliminating disturblng effects in such circuits due tothe use of periodically fluctuating voltage sources of sup- 1 p Thenovel features which I believe to be characteristic of my invention areset forth with particularity in the appended claims my invention itself,however, both as to its organization and method of operation will bestbe understood by reference to the following description taken inconnection with the accompanying drawing in which Figs. 1 and 2 showdiagrammatically two difierent circuit arrangements whereby my inventionmay be carried into eflI'ect.

In Fig. 1 I have indicated an electron discharge device 1 having acathode 2 adapted to emit electrons, two anodes 3 and 4, and two grids 5and 6. Grid 5 may be employed in the usual manner for controlling thecurrent between cathode 2 and anode 4 by connecting the source ofcontrolling voltage to conductors 7 and 8 in the usual manner foremploying the device as an amplifier or as a detector.

Anodes 3 and 4 are connected together and the plate or anode circuit ofthe device is supplied with current from a direct current generator 9.The use of a direct current generator as a source of plate supply givesrise to disagreeable noises in the telephone receivers 10 in the platecircuit due to commutation ripples, etc., it special means is notprovided to eliminate the efi'ect of the voltage fluctuations of thegenerator. It has been customary in the past to use large and somewhatexpensive filter coils for this purpose.

I overcome the effect of the voltage fluctuations of the source 9 byconnecting the grid 6 by means of a potentiometer connection to theresistance 11, which is connected adjacent the negative terminal ofgenerator 9. The anodes 3 and 4 are connected by means of anotherpotentiometer connection to a point in resistance 12, which is in serieswith resistance 11. The cathode 2 is connected to a point 13 betweenresistances 11 and 12. With 50 this connection any point in resistance11 will be negative with respect to the junction point 13, and hence thegrid 6 will always be negative with respect to the cathode 2.

The operation of the system described is as follows :Assume that thecircuit is out of adjustment and that disagreeable noises are heard inthe telephone 10 due to the voltage fluctuations of the generator. maythen be moved along resistance 11 until a balance is obtained andsilence occurs in the tential variations impressed upon grid 6 will Theslider.

be of the proper phase to compensate for the variations in plate currentdue to fluctuations in the voltage of the source 9. If the voltage ofsource 9 increases the current through resistance 11 will tend toincrease and this will cause an increase in the negative potentialapplied to grid 6. This increased negative potential will in turncounteract the tendency toward an increase in plate current. On theother hand, a decrease in the voltage of source 9 will cause a decreasein the negative potential of grid 6, and permit the current flowing toplate 3 to increase thus counteracting the tendency for the current inthe plate circuit to decrease.

In Fig. 2 I have indicated the application of my invention to a radioreceiving system comprising three electron discharge devices 14, 15 and16, having their plate circuits supplied with current from analternating current source 17 through electron discharge rectifiers 18and 19. Device 14 is connected to serve as a detector and devices 15 and16 are provided with two grids 20 and 21. Grids 20 perform the usualfunction of controlling the current to the plates. The currents suppliedto the plate circuits flow through resistance 22 and grids 21 areconnected to a point in this resistance by means of the slidingconnection 23. The operation of the system shown in Fig. 2 issubstantially the same as that of Fig. 1. The fluctuations in therectified potential supplied to the plates are partly eliminated by thesmoothing condenser 24 and the effect of the remaining fluctuations iscounteracted by the potentials applied to grids 21.

While I have shown and described only two embodiments of my invention itwill be apparent that many modifications in the apparatus and circuitconnections employed may be made without departing from the scope of myinvention as set forth in the ap pended claims.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is

' l. The combination with an electron discharge device having anelectron emitting cathode, an anode and a plurality of grids, of asource of periodically fluctuating voltage connected in the anodecircuit, and means for impressing upon a circuit connected between thecathode and one of the grids periodic voltage fluctuations of the properphase and value to neutralize the efl'cct in the anode circuit of thedevice of the voltage fluctuations of the source connected therein.

2. The combination with an electron dis charge device having an electronemitting cathode, an anode and a plurality of grids of a source ofperiodically fluctuating vol age connected in the anode circuit andmeans for impressing upon the circuit connected between the cathode andone of the grids periodic voltage fluctuations derived from said sourceof the proper phase and value to neutralize the effect in the anodecircuit of the device of the voltage fluctuations of the sourceconnected therein. 3. The combination with an electron dis charge devicehaving an electron emitting cathode, and anode and a plurality of grids,of a source of periodically fluctuating voltage connected in the anodecircuit, a resistance in the anode circuit and a connection from one ofthe grids to a point in said resistance for impressing upon that gridperiodic voltage fluctuations of the proper phase and value toneutralize the effect in the anode circuit of the voltage fluctuationsoi the source connected therein.

4. The combination with an electron discharge device having an electronemitting cathode, an anode and a plurality of grids of a source offluctuating voltage connected in the anode circuit, means for impressingupon a circuit connected between the cathode and one of the gridsvoltage fluctuations of the proper phase and value to neutralize theefl'ect in the anode circuit of the device of the voltage fluctuationsof the source connected therein, and means for impressing signallingpotentials upon another of said grids.

5. The combination in a system for the reception of signals of anelectron discharge device having an electron emitting cathode, an anodeand a plurality of grids and circuits connecting said cathode and saidanode and grids, one of said grid circuits having connections forreceiving currents to be detected and another of said grid circuitshaving associatcd therewith means for supplying a suitable potential toeliminate undesired currents in the anode circuit.

6. The combination with an electron discharge device having an electronemitting cathode, an anode and a plurality of grids, of a source ofrectified alternating voltage connected in the anode circuit, and meansfor impressing upon a circuit connected between the cathode and one ofthe grids voltage fluctuations derived from said source and of theproper phase and value to neutralize the effect in the anode circuit ofthe device of the voltage fluctuations of the source connected therein.

7. The combination with an electron discharge device having an electronemitting cathode, an anode and a plurality of grids, of a source ofrectified alternating voltage connected in the anode circuit, and meansfor impressing upon a circuit connected between the cathode and one ofthe grids voltage fluctuations derived from said source and of theproper phase and value to neutralize the efiiect in the anode circuit ofthe device of the voltage fluctuations or" the source connected therein,and means for impressing signaling potentials upon another of saidgrids.

8. The combination in a receiving system of a plurality of electrondischarge devices connected in cascade, each of said devices havin anelectron emitting cathode, an anode and a plurality of grids, a sourceof periodically fluctuating voltage connected in the anode circuits ofall of said devices, and means for impressing upon circuits connectedbetween the cathode and one grid of each device periodic voltagefluctuations of the proper phase and value to neutralize the effeet inthe anode circuits of the devices of the voltage fluctuations of thesource.

9. The combination in a receiving system of a plurality of electrondischarge devices connected in cascade, each of said devices having anelectron emitting cathode, an anode and a. plurality of grids, a sourceof rectified alternating voltage connected in the anode circuits of allof said devices, and means for impressing upon circuits connectedbetween the cathode and one grid of each device voltage fluctuationsderived from said source of the proper phase and value to neutralize theeffect in the anode circuits of the devices of the voltage fluctuationsof the source.

10. The combination with an electron discharge device having an electronemitting cathode, an anode and a grid of a source of periodicallyfluctuating voltage connected in the anode circuit, and means forimpressing upon a circuit connected between the cathode and the gridperiodic voltage fluctuations of v the proper phase and value toneutralize the .efiect in the anode circuit of the device of the voltagefluctuations of the source connected therein.

11. The combination with an electron discharge device having an electronemitting cathode, an anode and a grid of a source of periodicallyfluctuating voltage connected in the anode circuit, and means forimpressing upon a circuit associated with said device periodic voltagefluctuations of the proper phase and value to neutralize the eifect inthe anode circuit of the device of the voltage fluctuations of thesource connected therein.

12. The combination'with an electron discharge device having an electronemittin cathode, an anode and a grid of a source 0 fluctuating voltage,a resistance connected between the cathode and anode and a secondresistance connected between the cathode and grid, said resistancesbeing connected in series with one another and in shunt to thefluctuating voltage source in such a way that v the voltage drop acrossthe second resistance serves to impress upon the grid a voltage which"is always negative with respect to that of the cathode and whichfluctuates in opposite phase with the voltage fluctuations impressedupon the anode.

13. The combination with an electron discharge device having an electronemittin cathode, an anode and a grid of a source 0 rectified alternatingvoltage connected to the anode circuit of said device, a resistanceconnected in series with said source and a connectlon to the grld from apoint in sald resistance which is always at a negative potential withrespect to the cathode, said point being so chosen that the voltagefluctuations produced across said resistance and impressed upon the gridare of such value as to neutralize the effect in the anode circuit ofthe voltage fluctuations of saidsource.

14. In a system for supplying operating voltages to an electrondischarge device having a cathode, an anode and-a grid, a source ofperiodically fluctuating voltage, a resistance connected to said sourceand individual connections from each of the electrodes of said device tosaid resistance, said connections being so made that the potentialimpressed from said resistance upon the grid is always negative withrespect to that of the cathode and fluctuates in opposite phase to thevoltage fluctuations impressed upon the anode.

In witness whereof. I have hereunto set my hand this 1st day of October,1923.

GLENN W. CARPENTER.

-DISOL.AIMER Y 1,792,275.Glenn W. Carpenter, Schenectady, N. Y. CIRCUITSron ELECTRON- DISCHARGE DEVICES. Patent dated February 10, 1931.Disclaimer filed November 24, 1934, by the assignee, General ElectricCompany. V

Hereby enters this disclaimer to that part of the'claim in saidspecification which is in the following words, to wit:

14. In a system for supplying operating voltages to an electrondischarge device having a cathode, an anode and a grid, a source ofperiodically fluctuating voltage, a resistance connected to said sourceand individual connections from each of the electrodes of said device tosaid resistance, said connections being so made that the potentialimpressed from said resistance upon the grid is always negative withrespect to that of the cathode and fluctuates in opposite phase to thevoltage fluctuations impressed upon the anode.

[Qfic'ial Gazette December 18, 1.934.]

